Gasoline compositions

ABSTRACT

A gasoline composition is provided comprising:
     (i) base gasoline; and   (ii) a composition comprising component A and at least one component selected from component B, C, D and E wherein the concentration of the components in the composition is calculated using the equation:   

       Σ n=1   n=3   v   fn   E 70− E 70 base   =E 100 base −Σ n=1   n=3   v   fn   E 100 n  
     wherein:   n=1 is component B,   n=2 is component A,   n=3 is any one of components C, D or E,   v fn  is the volume fraction of the component n=1, 2 or 3 in the composition comprising component A and at least one component selected from components B, C, D and E,   E70 n  is the blending E70 value of the component represented by n,   E100 n  is the blending E100 value of the component represented by n,   E70 base  is in the range of from 10 to 55% vol., and   E100 base  is in the range of from 35 to 75% vol.

FIELD OF THE INVENTION

The present invention relates to an oxygenate composition suitable for use in gasoline.

BACKGROUND OF THE INVENTION

Esters are known components for use in fragrance and flavouring applications. In particular, ethyl valerate (also called ethyl pentanoate) is an ester commonly used in fragrance and flavouring applications.

JP57-115490-A1 (K.K. My-Skincare-Laboratories & Daikyu K. K.) discloses a kerosene deodoriser containing 1 kind or 2 or more kinds of lower fatty acid esters.

JP07-018269-A1 (Riken Koryo Kogyo K. K.) discloses fuel additives for suppressing the unpleasant odor characteristic of the fuel produced during incomplete combustion of said fuel. Gasoline is disclosed as one possible fuel for the fuel additives disclosed therein, and included in the list of compounds disclosed as being suitable for use as the fuel additive are a range of esters. JP07-018269-A1 mentions in passing that the fuel additives may be added to the fuel as they are or they can be added with other solvents, however, no details concerning which combinations of fuels, fuel additives and solvents would be applicable is disclosed therein.

WO 01/36354 A1 (Ronyak) discloses compositions containing an odor-emitting hydrocarbonaceous material and an odor-suppressing amount of an aldehyde or a ketone, and a carboxylic acid ester. Gasoline is listed as one of many possible hydrocarbonaceous materials.

U.S. Pat. No. 2,228,662 and U.S. Pat. No. 2,334,006 (Standard Oil Company) discloses the addition of esters to motor fuels consisting essentially of branched chain paraffin hydrocarbons and having a relatively high anti-knock value to increase the anti-knock quality thereof.

US 2001/0034966 A1 discloses a method of reducing the vapour pressure of a C₃ to C₁₂ hydrocarbon-based motor fuel mixture containing 0.1 to 20% by volume of ethanol for conventional spark ignition internal combustion engines, wherein, in addition to an ethanol component (b) and a C₃ to C₁₂ hydrocarbon component (a), an oxygen-containing additive (c) selected from at least one of the following types of compounds: alcohol other than ethanol, ketone, ether, ester, hydroxy ketone, ketone ester, and a heterocyclic containing oxygen, is used in the fuel mixture in an amount of at least 0.05 by volume of the total fuel.

Due to environmental concerns, there is a growing demand for the use of bio-components, i.e. components derived from a biological source, in gasoline.

Ethanol is a well-known bio-component currently used in gasoline, however, it has been observed that the addition of ethanol to base gasoline has the effect of increasing the E70 and E100 of the formulated gasoline relative to the base gasoline. Therefore, in order to include significant quantities of ethanol in gasoline, the base gasoline to which it is added has to be specially formulated in order for the formulated gasoline to meet gasoline specifications around the world.

SUMMARY OF THE INVENTION

The present invention provides a gasoline composition comprising:

-   (i) a base gasoline; and -   (ii) a composition comprising component A and at least one component     selected from categories (a) and (b) below: -   (a) component B, and -   (b) one component selected from components C, D and E, wherein:

component A is an ester or mixture of esters having formula I:

R¹C(═O)—O—R²   (I)

wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.;

-   component B is ethanol; -   component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.;

component D is butanol; and

component E is an ether of the general formula IV:

R⁷—O—C(Me)₃   (IV)

wherein R⁷ is selected from methyl, ethyl or mixtures thereof, wherein the concentration of the components in the composition is calculated using the following equation (equation I):

Σ_(n=1) ^(n=3) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I)

wherein:

-   n=1 is component B, -   n=2 is component A, -   n=3 is any one of components C, D or E, -   v_(fn) is the volume fraction of the component n=1, 2 or 3 in the     composition comprising component A and at least one component     selected from components B, C, D and E, -   E70_(n) is the blending E70 value of the component represented by n, -   E100_(n) is the blending E100 value of the component represented by     n, -   E70_(base) is in the range of from 10 to 55% vol., and -   E100_(base) is in the range of from 35 to 75% vol.

The present invention further provides a process for the preparation of a gasoline composition according to the present invention, said process comprising bringing into admixture with the base gasoline, a composition comprising component A and at least one component selected from categories (a) and (b) below:

-   (a) component B, and -   (b) one component selected from components C, D and E.

The present invention yet further provides a process for the preparation of a gasoline composition according to the present invention, said process comprising bringing into admixture with the base gasoline, component A and at least one component selected from categories (a) and (b) below:

-   (a) component B, and -   (b) one component selected from components C, D and E.

The present invention yet further provides a method of operating a spark-ignition internal combustion engine, which comprises bringing into the combustion chambers of said engine a gasoline composition according to the present invention.

The present invention yet further provides a gasoline composition comprising:

-   (i) a base gasoline; and -   (ii) a composition comprising component A, component B and at least     one other oxygenate component selected from components C, D and E,     wherein:

component A is an ester or mixture of esters having formula I:

R¹C (═O)—O—R²   (I)

wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.;

component B is ethanol;

component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.;

component D is butanol; and

component E is an ether of the general formula IV:

R⁷—O—C(Me)₃   (IV)

wherein R⁷ is selected from methyl, ethyl or mixtures thereof, wherein the concentration of the components in the composition is calculated using the following equation (equation I):

Σ_(n=1) ^(n=3) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I)

wherein:

-   n=1 is component B, -   n=2 is component A, -   n=3 is any one of components C, D or E, -   v_(fn) is the volume fraction of the component n=1, 2 or 3 in the     composition comprising component A and at least one component     selected from components B, C, D and E, -   E70_(n) is the blending E70 value of the component represented by n, -   E100_(n) is the blending E100 value of the component represented by     n, -   E70_(base) is in the range of from 10 to 55% vol., and -   E100_(base) is in the range of from 35 to 75% vol.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE represents the volume fraction of the three components according to the invention in a triangle plot.

DETAILED DESCRIPTION OF THE INVENTION

It has now been found that blends of certain oxygenates can be prepared that can be blended with base gasoline to provide a gasoline composition without significantly altering the E70 and E100 value of the base gasoline.

The composition of the present invention comprises component A and at least one component selected from components B, C, D and E.

The composition of the present invention preferably comprises component A and at least one component selected from categories (a) and (b) below:

-   (a) component B, and -   (b) one component selected from components C, D and E.

i.e. the composition of the present invention preferably comprises any of the following mixtures of components A, B, C, D and E:

Component A and component B;

Component A and component C;

Component A and component D;

Component A and component E;

Component A, component B and component C;

Component A, component B and component D; and

Component A, component B and component E.

In one specific embodiment of the present invention, the composition of the present invention comprises component A and one component selected from components C, D and E, and optionally comprises component B.

Component A is an ester or mixture of esters having formula I:

R¹C(═O)—O—R²   (I)

wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.;

Preferably, R¹ is selected from a C₂₋₅ alkyl group, more preferably a C₃₋₅ alkyl group, and especially a C₄ alkyl group.

Preferably R² is selected from a C₁₋₄ alkyl group, more preferably a C₁₋₃ alkyl group, and especially a C₂ alkyl group.

Preferably the total number of carbon atoms in R¹ and R² is in the range of from 5-8, more preferably in the range of from 6-7.

The boiling point or boiling point range of component A is preferably within the temperature range of from 95 to 180° C., more preferably within the temperature range of from 100 to 170° C.

Examples of particularly suitable esters include methyl valerate (methyl pentanoate), ethyl valerate (ethyl pentanoate), propyl valerate (propyl pentanoate), methyl hexanoate, ethyl hexanoate and propyl hexanoate and mixtures thereof.

Most preferably component A is ethyl valerate.

Component B is ethanol.

Component C is a compound or mixture of compounds having formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.

Preferably, one or two of the R³, R⁴, R⁵ and R⁶ groups are independently selected from C₁₋₆ hydrocarbyl groups, with the remaining R³, R⁴, R⁵ and R⁶ groups being hydrogen. More preferably, the R⁴ and R⁵ groups are hydrogen and the R³ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with at least one of the R³ and R⁶ groups being a 1-6 hydrocarbyl group.

Preferably, the C₁₋₆ hydrocarbyl groups are C1-6 alkyl groups, more preferably methyl, ethyl and propyl groups.

The boiling point or boiling point range of component C is preferably within the temperature range at most 105° C., more preferably at most 100° C. Typically, the boiling point or boiling point range of component C is within the range of from 40 to 110° C., more typically within the temperature range of from 50 to 105° C., most typically within the temperature range of from 60 to 100° C.

Examples of suitable compounds according to formula II include 2-methyl furan, 3-methyl furan, 2-ethyl furan, 3-ethyl furan, 2,5-dimethyl furan, 2,5-diethyl furan and 2-methyl-5-ethyl furan, and mixtures thereof. Examples of suitable compounds according to formula III include 2-methyl tetrahydrofuran, 3-methyl tetrahydrofuran, 2-ethyl tetrahydrofuran, 3-ethyl tetrahydrofuran, 2,5-dimethyl tetrahydrofuran, 2,5-diethyl tetrahydrofuran and 2-methyl-5-ethyl tetrahydrofuran, and mixtures thereof.

Most preferably component C is selected from 2-methyl furan, 2,5-dimethyl furan and mixtures thereof.

Component D is butanol.

Component E is an ether of the general formula IV.

R⁷—O—C(Me)₃   (IV)

Wherein R⁷ is selected from methyl, ethyl or mixtures thereof.

The composition of the present invention is suitable for blending with a base gasoline to form a gasoline composition.

Components A, B, C and D can be derived from a biological source using methods known in the art, therefore compositions according to the present invention may be partially or entirely derived from a biological source material and therefore be included in a gasoline composition as a biofuel component. Preferably, at least one of components A to D is derived from a biological source material.

Advantageously, by varying the relative concentrations of the at least two different components in the composition of the present invention, it allows the formation of a gasoline component that has a reduced impact on the Dry Vapour Pressure Equivalent (DVPE) (EN 13016-1), E70 (% vol. evaporated at 70° C., as determined by EN ISO 3405) and E100 (% vol. evaporated at 100° C., as determined by EN ISO 3405) of the base gasoline to which it is to be blended, compared to the blending of a concentration equal to the concentration of the composition of the present invention of any of the individual components.

It has been found that for a given E70 and E100 of the base gasoline, a composition according to the present invention may be blended that will not significantly alter the E70 and E100 values in the formed gasoline composition. By the term “not significantly alter the E70 and E100 values” it is meant that both the E70 value and the E100 value of the formulated gasoline composition is maintained within 25%, preferably within 20%, more preferably within 15%, of both the E70 value and the E100 value of the base gasoline, and the value of E70+E100 will be maintained within 15%, preferably within 10%, more preferably within 5% of the value of E70+E100 of the base gasoline.

The concentrations of the two or three components of the composition of the present invention can be represented in a triangle plot as shaded area “G” in the FIGURE and can be described using the following equation (equation I):

Σ_(n=1) ^(n=3) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I)

wherein:

-   n=1 is component B, -   n=2 is component A, -   n=3 is any one of components C, D or E, -   v_(fn) is the volume fraction of the component n=1, 2 or 3 in a the     composition comprising component A and at least one component     selected from components B, C, D and E, -   E70_(n) is the blending E70 value of the component represented by n, -   E100_(n) is the blending E100 value of the component represented by     n, -   E70_(base) is in the range of from 10 to 55% vol., and -   E100_(base) is in the range of from 35 to 75% vol.

The E70_(base) value is preferably in the range of from 14 to 51% vol., more preferably in the range of from 14 to 50% vol., and most preferably in the range of from 20 to 50% vol. In one embodiment of the present invention, the E70_(base) value is in the range of from 20 to 48% vol. In an alternative embodiment of the present invention, the E70_(base) value is in the range of from 22 to 50% vol. It is especially preferred that the E70_(base) value is the E70 value of the base gasoline.

The E100_(base) value is preferably in the range of from 40 to 72% vol., more preferably in the range of from 40 to 71% vol., and most preferably in the range of from 46 to 71% vol. It is especially preferred that the E100_(base) value is the E100 value of the base gasoline.

The blending E70_(n) and E100_(n) values for components A, B, C, D and E are average values determined from data collected on base fuels containing the single oxygenate component (n=A, B, C, D or E) added across a range of blend ratios. The E70_(n) and E100_(n) values are determined according to equations II and III below:

$\begin{matrix} {{E\; 70_{n}} = \frac{{E\; 70_{blend}} - {E\; 70_{base}\left( {1 - v_{fn}} \right)}}{v_{fn}}} & \left( {{equation}\mspace{14mu} {II}} \right) \\ {{E\; 100_{n}} = \frac{{E\; 100_{blend}} - {E\; 100_{base}\left( {1 - v_{fn}} \right)}}{v_{fn}}} & \left( {{equation}\mspace{14mu} {III}} \right) \end{matrix}$

wherein:

-   n is component A, B, C, D or E -   v_(fn) is the volume fraction of the component A, B, C, D or E when     combined with a base gasoline -   E70_(base) is the E70 value of the base gasoline used -   E100_(base) is the E100 value of the base gasoline used -   E70_(blend) is the E70 value of the base gasoline combined with     component A, B, C, D or E, and -   E100_(blend) is the E100 value of the base gasoline combined with     component A, B, C, D or E.

Currently, the EN228 gasoline specification specifies that the E70 value is in the range of from 20 to 50% vol., specifically for summer gasoline the E70 value is in the range of from 20 to 48% vol. and for winter gasoline E70 value is in the range of from 22 to 50% vol., and the E100 value is in the range of from 46 to 71% vol. Therefore, the E70_(base) value and the E100_(base) value are conveniently in the ranges specified in the EN228 gasoline specification.

Thus, the composition of the present invention may be blended with a base gasoline that complies with current gasoline specifications (e.g. EN228) in relation to DVPE, E70 and E100, to form a gasoline composition which still complies with same gasoline specification relating to DVPE, E70 and E100.

Usefully, because at least one of components A to E can be derived from a biological source material and the fact that compositions according to the present invention may be blended with a base gasoline without significantly altering the E70 and E100 values, the composition of the present invention can be used in order to maximize the bio-energy content of a gasoline composition.

The compositions of the present invention typically have high RON (Research Octane Number) and MON (Motor Octane Number) values, and therefore may be also be used to increase the RON and/or MON of a base gasoline.

The present invention also provides a gasoline composition comprising:

-   (i) base gasoline; and -   (ii) a composition comprising component A and at least one component     selected from components B, C, D and E, as described above.

Further, the present invention also provides a gasoline composition comprising:

-   (i) a base gasoline; and -   (ii) a composition comprising component A, component B and at least     one component selected from components C, D and E as described     above.

The gasoline composition according to the present invention may be prepared by blending the base gasoline with component A and at least one component selected from components B, C, D and E. The order in which the base gasoline and components A to E are combined is not critical. Therefore, the gasoline composition of the present invention can also be described as comprising:

-   (i) base gasoline; and -   (ii) component A and at least one component selected from components     B, C, D and E, as described above.

Yet further, the gasoline composition according to the present invention may be prepared by blending the base gasoline with component A, component B and at least one other oxygenate component selected from components C, D and E. The order in which the base gasoline and components A to E are combined is not critical.

The preferred relative concentrations of components A to E in the gasoline composition are as described above and are calculated on the basis of a composition comprising component A and at least one component selected from components B, C, D and E, in the absence of the base gasoline, whether or not such a composition is prepared prior to combining components A to E with the base gasoline.

If the composition of the present invention comprises components A, B and C, then the concentration of the composition preferably comprises:

-   From 25 to 76% vol. of component A; -   From 0.1 to 39% vol. of component B; and -   From 0.1 to 75% vol. of component C.

If the composition of the present invention comprises components A, B and D, then the concentration of the composition preferably comprises:

-   From 0.1 to 76% vol. of component A; -   From 0.1 to 39% vol. of component B; and -   From 0.1 to 99.9% vol. of component D.

If the composition of the present invention comprises components A, B and E, then the concentration of the composition preferably comprises:

-   From 12 to 76% vol. of component A; -   From 0.1 to 39% vol. of component B; and -   From 0.1 to 88% vol. of component E.

The concentration, based on the overall gasoline composition, of the composition comprising component A and at least one component selected from components B, C, D and E, as described above, which can be blended with the base gasoline to form a gasoline composition according to the present invention preferably accords with one of parameters (i) to (v) below, or a combination of one of parameters (i) to (v) and one of parameters (vi) to (x):—

-   (i) at most 40% vol.; -   (ii) at most 35% vol.; -   (iii) at most 30% vol.; -   (iv) at most 25% vol.; -   (v) at most 20% vol.;     with features (i), (ii), (iii), (iv) and (v) being progressively     more preferred; and -   (vi) at least 0.5% vol.; -   (vii) at least 1.0% vol.; -   (viii) at least 2.0% vol.; -   (ixi) at least 3.0% vol.; -   (x) at least 5.0% vol.;     with features (vi), (vii), (viii), (ix) and (x) being progressively     more preferred.

The concentration of the composition comprising component A and at least one component selected from components B, C, D and E, is calculated on the basis of a composition comprising component A and at least one component selected from components B, C, D and E, in the absence of the base gasoline, whether or not such a composition is prepared prior to combining components A to E with the base gasoline.

Ranges having a combination of any feature selected from (i) through (v) above and any feature selected from (vi) through (x) above are particularly applicable in the gasoline compositions provided by present invention. Examples of specific combinations of the above features include (i) and (vi), (ii) and (vii), (iii) and (viii), (iv) and (ix), and (v) and (x), respectively being progressively more preferred.

The base gasoline to which the composition of the present invention can be blended with may be any gasoline suitable for use in an internal combustion engine of the spark-ignition (petrol) type known in the art.

The base gasoline typically comprises mixtures of hydrocarbons boiling in the range from 25 to 230° C. (EN-ISO 3405), the optimal ranges and distillation curves typically varying according to climate and season of the year. The hydrocarbons in a gasoline base fuel may be derived by any means known in the art, conveniently the hydrocarbons may be derived in any known manner from straight-run gasoline, synthetically-produced aromatic hydrocarbon mixtures, thermally or catalytically cracked hydrocarbons, hydro-cracked petroleum fractions, catalytically reformed hydrocarbons or mixtures of these.

The specific distillation curve, hydrocarbon composition, research octane number (RON) and motor octane number (MON) of the gasoline base fuel are not critical.

Conveniently, the research octane number (RON) of the gasoline base fuel may be in the range of from 80 to 110, preferably from 90 to 105, more preferably from 93 to 102, most preferably from 94 to 100 (EN 25164); the motor octane number (MON) of the gasoline base fuel may suitably be in the range of from 70 to 110, preferably from 75 to 105, more preferably from 80 to 100, most preferably from 84 to 95 (EN 25163).

Typically, gasoline base fuels comprise components selected from one or more of the following groups; saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and oxygenated hydrocarbons. Conveniently, the gasoline base fuel may comprise a mixture of saturated hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and, optionally, oxygenated hydrocarbons.

Typically, the olefinic hydrocarbon content of the gasoline base fuel is in the range of from 0 to 40 percent by volume based on the gasoline base fuel; preferably, the olefinic hydrocarbon content of the gasoline base fuel is in the range of from 0 to 30 percent by volume based on the gasoline base fuel.

Typically, the aromatic hydrocarbon content of the gasoline base fuel is in the range of from 0 to 70 percent by volume based on the gasoline base fuel; preferably, the aromatic hydrocarbon content of the gasoline base fuel is in the range of from 10 to 60 percent by volume based on the gasoline base fuel.

The benzene content of the gasoline base fuel is at most 10 percent by volume, more preferably at most 5 percent by volume, especially at most 1 percent by volume based on the gasoline base fuel.

Typically, the saturated hydrocarbon content of the gasoline base fuel is at least 40 percent by volume based on the gasoline base fuel; preferably, the saturated hydrocarbon content of the gasoline base fuel is in the range of from 40 to 80 percent by volume based on the gasoline base fuel.

The gasoline base fuel preferably has a low or ultra low sulphur content, for instance at most 1000 ppmw (parts per million by weight), preferably no more than 500 ppmw, more preferably no more than 100, even more preferably no more than 50 and most preferably no more than even 10 ppmw.

The gasoline base fuel also preferably has a low total lead content, such as at most 0.005 g/l, most preferably being lead free—having no lead compounds added thereto (i.e. unleaded).

When the gasoline comprises oxygenated hydrocarbons, at least a portion of non-oxygenated hydrocarbons will be substituted for oxygenated hydrocarbons.

The oxygenated hydrocarbons that may be included in the gasoline base fuel are oxygenated components other than components A to E described herein. If the base gasoline contains an oxygenated component of the type described by components A to E, then this component is to be considered as a component of the composition according to the present invention and the relative quantities of the other components A to E will be adjusted accordingly.

Examples of suitable gasoline base fuels include gasoline base fuels which have an olefinic hydrocarbon content of from 0 to 20 percent by volume (ASTM D1319), an oxygen content of from 0 to 5 percent by weight (EN 1601), an aromatic hydrocarbon content of from 0 to 50 percent by volume (ASTM D1319) and a benzene content of at most 1 percent by volume.

Whilst not critical to the present invention, the gasoline base fuel or the gasoline composition of the present invention may conveniently additionally include one or more fuel additive. The concentration and nature of the fuel additive(s) that may be included in the gasoline base fuel or the gasoline composition of the present invention is not critical. Non-limiting examples of suitable types of fuel additives that can be included in the gasoline base fuel or the gasoline composition of the present invention include anti-oxidants, corrosion inhibitors, detergents, dehazers, antiknock additives, metal deactivators, valve-seat recession protectant compounds, dyes, friction modifiers, carrier fluids, diluents and markers. Examples of suitable such additives are described generally in U.S. Pat. No. 5,855,629.

Conveniently, the fuel additives can be blended with one or more diluents or carrier fluids, to form an additive concentrate, the additive concentrate can then be admixed with the gasoline composition or gasoline base fuel.

The (active matter) concentration of any additives present in the gasoline base fuel or the gasoline composition is preferably up to 1 percent by weight, more preferably in the range from 5 to 1000 ppmw, advantageously in the range of from 75 to 300 ppmw, such as from 95 to 150 ppmw.

A gasoline composition according to the present invention may be prepared by a process which comprises bringing into admixture with the base gasoline, a composition comprising component A and at least one of components B, C, D and E, and optionally other conventional gasoline components, such as one or more fuel additives. As explained above, it is not critical that the composition comprising component A and at least one of components B, C, D and E is formed prior to blending with the base gasoline, provided that component A and at least one of components B to E are brought into admixture with the base gasoline (i.e. the composition may formed in-situ).

Therefore, the present invention provides a process for the preparation of a gasoline composition as described above, said process comprising bringing into admixture with the base gasoline, a composition comprising component A and at least one component selected from categories (a) and (b) below:

-   (a) component B, and -   (b) one component selected from components C, D and E.

Alternatively, the present invention provides a process for the preparation of a gasoline composition as described above, said process comprising bringing into admixture with the base gasoline, component A and at least one component selected from categories (a) and (b) below:

-   (a) component B, and -   (b) one component selected from components C, D and E.

If the gasoline composition additionally comprises one or more fuel additives, then the one or more fuel additive, or the additive concentrate, may be admixed with one or more of the constituents of the gasoline composition (e.g. component A, component B, component C, component D, component E, or the composition comprising component A and at least one component selected from categories (a) and (b) as described above, and the base gasoline) or with the gasoline composition itself. If the one or more fuel additive is added to more than one of the constituents of the gasoline composition, then the fuel additive added to each of the constituents of the gasoline composition may be the same or different.

The present invention also provides a method of operating a spark-ignition internal combustion engine, which comprises bringing into the combustion chambers of said engine a gasoline composition as defined above.

The present invention will be further understood from the following examples. Unless otherwise indicated, parts and percentages (concentration) are by volume (% v/v) and temperatures are in degrees Celsius (° C.).

Examples Comparative Examples A to C

The base gasoline used in comparative examples A to C was an EN 228 unleaded gasoline having the specific properties detailed in Table 1 below:

TABLE 1 Property RON 96.1 MON 85.1 RVP (kPa) 81.7 Density (kg/m³) 742.6 FBP (° C.) 202.0 Residue (% v) 1.0 E70 (% v) 29.6 E100 (% v) 48.7 E150 (% v) 85.6

The base gasoline described in Table 1 above and blends of the base gasoline with 10% vol. and 20% vol. ethyl valerate (EV), based on the volume of the formulated gasoline composition, were prepared.

The properties of each of the gasoline compositions are provided in Table 2 below.

TABLE 2 Base Gasoline EV RVP E70 E100 E70 + Example (% v/v) (% v/v) (kPa) (% v) (% v) E100 A 100 0 81.7 29.6 48.7 78.3 B 90 10 76.2 25.4 42.6 68 C 80 20 70.1 21.8 37.2 59

Comparative Examples D to G

The base gasoline used in comparative examples D to G was an EN 228 unleaded gasoline having the specific properties detailed in Table 3 below:

TABLE 3 Property RON 92.2 MON 83.0 Density (kg/m³) 740.9 FBP (° C.) 193.4 E70 (% v) 36.2 E100 (% v) 61.8 E150 (% v) 89.4

The base gasoline described in Table 3 above and blends of the base gasoline with 5% vol., 10% vol. and 20% vol. ethanol (EtOH), based on the volume of the formulated gasoline composition, were prepared.

The properties of each of the gasoline compositions are provided in Table 4 below.

TABLE 4 Base Gasoline EtOH E70 E100 E70 + Example (% v/v) (% v/v) (% v) (% v) E100 D 100 0 36.2 61.8 89.4 E 95 5 44.7 65.2 91.4 F 90 10 55.2 66.0 90.7 G 80 20 74.8 74.8 91.6

Comparative Example H and Examples 1 to 16

The properties several gasoline compositions containing compositions according to the present invention are given below.

The base gasoline used in the following examples was an EN 228 unleaded gasoline having the specific properties detailed in Table 5 below.

TABLE 5 Property RON 95.7 MON 85.2 RVP (kPa) 88.9 Density (kg/m³) 731.5 IBP (° C.) 27.2 FBP (° C.) 199.5 Residue (% v) 1.0 Recovery (% v) 94 Loss (% v) 5.0 10% evap (° C.) 40.6 20% evap (° C.) 51.7 30% evap (° C.) 64.2 40% evap (° C.) 78.2 50% evap (° C.) 92.4 60% evap (° C.) 105.6 70% evap (° C.) 117.8 80% evap (° C.) 133.4 90% evap (° C.) 156.2 95% evap (° C.) 173.1 E70 (% v) 34.3 E100 (% v) 55.5 E120 (% v) 71.6 E150 (% v) 87.5 E180 (% v) 96.4

The ethyl valerate used was supplied by Sigma-Aldrich and had a purity of 99%.

The ethanol (anhydrous) used was supplied by Sigma-Aldrich and had a purity of >99%.

The 2-methyl furan used was supplied by Sigma-Aldrich and had a purity of 99%.

To prepare the gasoline compositions, four separate compositions according to the present invention were prepared and are detailed in Table 6 below.

TABLE 6 2-Methyl Ethyl Valerate Ethanol Furan Example Composition (% v/v) (% v/v) (% v/v) 1 Ox1 42 0 58 2 Ox2 51 10 39 3 Ox3 60 20 20 4 Ox4 70 30 0

Using the above four oxygenate compositions (Ox1 to Ox4), twelve different gasoline compositions were prepared by admixing each of the above oxygenate compositions (Ox1, Ox2, Ox3 and Ox4) individually with the base gasoline detailed in Table 5, at 5% vol., 10% vol. and 20% vol. concentrations based on the volume of the formulated gasoline composition.

The properties of each of the gasoline compositions are provided in Table 7 below.

TABLE 7 Base Gasoline Oxygenate (% v/v) RVP E70 E100 E70 + Example (% v/v) Ox1 Ox2 Ox3 Ox4 (kPa) (% v) (% v) E100 H 100 88.9 34.3 55.5 89.8  5 95 5 87.4 35 56.6 91.6  6 95 5 90.2 34 55.4 89.4  7 95 5 90.3 33.7 54.3 89.0  8 95 5 92.2 34.3 53.9 88.2  9 90 10 84.2 33.5 56.3 89.8 10 90 10 87.5 34.1 55.2 89.3 11 90 10 88.8 34.5 53.9 88.4 12 90 10 87.9 34.9 52.2 87.1 13 80 20 76.6 32.3 56.9 89.2 14 80 20 82.2 33.9 54.8 88.7 15 80 20 82.9 34.7 51.5 86.2 16 80 20 83.5 37.5 51.3 88.8

It can clearly be seen that the E70, E100 and the E70+E100 values of the gasoline compositions according to the present invention are not significantly altered from the E70 and E100 values of the base gasoline (comparative Example H), and the E70 and E100 values of the gasoline compositions according to the present invention are well within the current EN 228 gasoline specifications.

FIGURE represents the volume ratios of ethanol, ethyl valerate and 2-methyl furan within the golden region “G” that can be blended with RBOB fuels having 20-50% v E70 and 46-71% v E100 and result in ΔRVP≦0 kPa and ΔE70+ΔE100=0% v. 

1. A gasoline composition comprising: (i) a base gasoline; and (ii) a composition comprising component A and at least one component selected from categories (a) and (b) below: (a) component B, and (b) one component selected from components C, D and E, wherein: component A is an ester or mixture of esters having formula I: R¹C(═O)—O—R²   (I) wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.; component B is ethanol; component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.; component D is butanol; and component E is an ether of the general formula IV: R⁷—O—C(Me)₃   (IV) wherein R⁷ is selected from methyl, ethyl or mixtures thereof, wherein the concentration of the components in the composition is calculated using the following equation (equation I): Σ_(n=1) ^(n=2) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I) wherein: n=1 is component B, n=2 is component A, n=3 is any one of components C, D or E, v_(fn) is the volume fraction of the component n=1, 2 or 3 in the composition comprising component A and at least one component selected from components B, C, D and E, E70_(n) is the blending E70 value of the component represented by n, E100_(n) is the blending E100 value of the component represented by n, E70_(base) is in the range of from 10 to 55% vol., and E100_(base) is in the range of from 35 to 75% vol.
 2. The gasoline composition of claim 1 wherein E70_(base) is in the range of from 20 to 50% vol., and E100_(base) is in the range of from 46 to 71% vol.
 3. The gasoline composition of claim 1 wherein E70_(base) is the E70 value of the base gasoline, and E100_(base) is the E100 value of the base gasoline.
 4. The composition of claim 1 wherein in component A, the R¹ group is a C₃₋₅ alkyl group, the R² group is a C₁₋₃ alkyl group, and with the proviso that component A has a boiling point or boiling point range within the temperature range of from 100 to 170° C.
 5. The gasoline composition of claim 1 wherein component A is ethyl valerate.
 6. The gasoline composition of claim 1 wherein in component C, the R⁴ and R⁵ groups are hydrogen, the R³ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with at least one of the R³ and R⁶ groups being a C₁₋₆ hydrocarbyl group, and with the proviso that component C has a boiling point or boiling point range of at most 100° C.
 7. The gasoline composition of claim 1 wherein component C is selected from 2-methyl furan, 2,5-dimethyl furan and mixtures thereof.
 8. The gasoline composition of claim 1 wherein the composition (ii) comprises component A and one component selected from components C, D and E, and optionally component B.
 9. The gasoline composition of claim 8 wherein the composition (ii) additionally comprises component B.
 10. The gasoline composition of claim 1 wherein the concentration of (ii) is in the range of from 0.5 to 40 % vol., based on the gasoline composition.
 11. A process for the preparation of a gasoline composition comprising providing a base gasoline and bringing into admixture with the base gasoline, a composition comprising component A and at least one component selected from categories (a) and (b) below: (a) component B, and (b) one component selected from components C, D and E wherein: component A is an ester or mixture of esters having formula I: R¹C(═O)—O—R²   (I) wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.; component B is ethanol; component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.; component D is butanol; and component E is an ether of the general formula IV: R⁷—O—C(Me)₃   (IV) wherein R⁷ is selected from methyl, ethyl or mixtures thereof, wherein the concentration of the components in the composition is calculated using the following equation (equation I): Σ_(n=1) ^(n=3) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I) wherein: n=1 is component B, n=2 is component A, n=3 is any one of components C, D or E, v_(fn) is the volume fraction of the component n=1, 2 or 3 in the composition comprising component A and at least one component selected from components B, C, D and E, E70_(n) is the blending E70 value of the component represented by n, E100_(n) is the blending E100 value of the component represented by n, E70_(base) is in the range of from 10 to 55% vol., and E100_(base) is in the range of from 35 to 75% vol.
 12. A process for the preparation of a gasoline composition comprising providing a base gasoline and bringing into admixture with the base gasoline, component A and at least one component selected from categories (a) and (b) below: (a) component B, and (b) one component selected from components C, D and E wherein: component A is an ester or mixture of esters having formula I: R¹C(═O)—O—R²   (I) wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.; component B is ethanol; component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.; component D is butanol; and component E is an ether of the general formula IV: R⁷—O—C(Me)₃   (IV) wherein R⁷ is selected from methyl, ethyl or mixtures thereof, wherein the concentration of the components in the composition is calculated using the following equation (equation I): Σ_(n=1) ^(n=3) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I) wherein: n=1 is component B, n=2 is component A, n=3 is any one of components C, D or E, v_(fn) is the volume fraction of the component n=1, 2 or 3 in the composition comprising component A and at least one component selected from components B, C, D and E, E70_(n) is the blending E70 value of the component represented by n, E100_(n) is the blending E100 value of the component represented by n, E70_(base) is in the range of from 10 to 55% vol., and E100_(base) is in the range of from 35 to 75% vol.
 13. A method of operating a spark-ignition internal combustion engine, which comprises bringing into the combustion chambers of said engine a gasoline composition of claim
 1. 14. A gasoline composition comprising: (i) a base gasoline; and (ii) a composition comprising component A, component B and at least one other oxygenate component selected from components C, D and E, wherein: component A is an ester or mixture of esters having formula I: R¹C(═O)—O—R²   (I) wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.; component B is ethanol; component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.; component D is butanol; and component E is an ether of the general formula IV: R⁷—O—C(Me)₃   (IV) wherein R⁷ is selected from methyl, ethyl or mixtures thereof, wherein the concentration of the components in the composition is calculated using the following equation (equation I): Σ_(n=1) ^(n=3) v _(fn) E70_(n) −E70_(base) =E100_(base)−Σ_(n=1) ^(n=3) v _(fn) E100_(n)   (equation I) wherein: n=1 is component B, n=2 is component A, n=3 is any one of components C, D or E, v_(fn) is the volume fraction of the component n=1, 2 or 3 in the composition comprising component A and at least one component selected from components B, C, D and E, E70_(n) is the blending E70 value of the component represented by n, E100_(n) is the blending E100 value of the component represented by n, E70_(base) is in the range of from 10 to 55% vol., and E100_(base) is in the range of from 35 to 75% vol.
 15. The gasoline composition of claim 14 wherein the one other oxygenate component is component C.
 16. The gasoline composition of claim 14 wherein the one other oxygenate component is component D.
 17. The gasoline composition of claim 14 wherein the one other oxygenate component is component E.
 18. A gasoline composition comprising: (i) a base gasoline; and (ii) a composition comprising component A, component B and at least one other oxygenate component selected from components C, D and E in a concentration according to area G in the FIGURE wherein: component A is an ester or mixture of esters having formula I: R¹C(═O)—O—R²   (I) wherein R¹ is selected from a C₁₋₆ alkyl group and R² is selected from a C₁₋₄ alkyl group and wherein the total number of carbon atoms in R¹ and R² is in the range of from 5-9, with the proviso that component A has a boiling point or boiling point range within the temperature range of from 90 to 200° C.; component B is ethanol; component C is a compound of formula II or formula III:

wherein the R³, R⁴, R⁵ and R⁶ groups are independently selected from hydrogen and C₁₋₆ hydrocarbyl groups, with the proviso that component C has a boiling point or boiling point range of at most 110° C.; component D is butanol; and component E is an ether of the general formula IV: R⁷—O—C(Me)₃   (IV) wherein R⁷ is selected from methyl, ethyl or mixtures thereof. 